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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 | // SPDX-License-Identifier: GPL-2.0-or-later /* * Cobalt/SEAD3 LCD frame buffer driver. * * Copyright (C) 2008 Yoichi Yuasa <yuasa@linux-mips.org> * Copyright (C) 2012 MIPS Technologies, Inc. */ #include <linux/delay.h> #include <linux/fb.h> #include <linux/init.h> #include <linux/io.h> #include <linux/ioport.h> #include <linux/uaccess.h> #include <linux/platform_device.h> #include <linux/module.h> #include <linux/sched/signal.h> /* * Cursor position address * \X 0 1 2 ... 14 15 * Y+----+----+----+---+----+----+ * 0|0x00|0x01|0x02|...|0x0e|0x0f| * +----+----+----+---+----+----+ * 1|0x40|0x41|0x42|...|0x4e|0x4f| * +----+----+----+---+----+----+ */ #define LCD_DATA_REG_OFFSET 0x10 #define LCD_XRES_MAX 16 #define LCD_YRES_MAX 2 #define LCD_CHARS_MAX 32 #define LCD_CLEAR 0x01 #define LCD_CURSOR_MOVE_HOME 0x02 #define LCD_RESET 0x06 #define LCD_OFF 0x08 #define LCD_CURSOR_OFF 0x0c #define LCD_CURSOR_BLINK_OFF 0x0e #define LCD_CURSOR_ON 0x0f #define LCD_ON LCD_CURSOR_ON #define LCD_CURSOR_MOVE_LEFT 0x10 #define LCD_CURSOR_MOVE_RIGHT 0x14 #define LCD_DISPLAY_LEFT 0x18 #define LCD_DISPLAY_RIGHT 0x1c #define LCD_PRERESET 0x3f /* execute 4 times continuously */ #define LCD_BUSY 0x80 #define LCD_GRAPHIC_MODE 0x40 #define LCD_TEXT_MODE 0x80 #define LCD_CUR_POS_MASK 0x7f #define LCD_CUR_POS(x) ((x) & LCD_CUR_POS_MASK) #define LCD_TEXT_POS(x) ((x) | LCD_TEXT_MODE) static inline void lcd_write_control(struct fb_info *info, u8 control) { writel((u32)control << 24, info->screen_base); } static inline u8 lcd_read_control(struct fb_info *info) { return readl(info->screen_base) >> 24; } static inline void lcd_write_data(struct fb_info *info, u8 data) { writel((u32)data << 24, info->screen_base + LCD_DATA_REG_OFFSET); } static inline u8 lcd_read_data(struct fb_info *info) { return readl(info->screen_base + LCD_DATA_REG_OFFSET) >> 24; } static int lcd_busy_wait(struct fb_info *info) { u8 val = 0; int timeout = 10, retval = 0; do { val = lcd_read_control(info); val &= LCD_BUSY; if (val != LCD_BUSY) break; if (msleep_interruptible(1)) return -EINTR; timeout--; } while (timeout); if (val == LCD_BUSY) retval = -EBUSY; return retval; } static void lcd_clear(struct fb_info *info) { int i; for (i = 0; i < 4; i++) { udelay(150); lcd_write_control(info, LCD_PRERESET); } udelay(150); lcd_write_control(info, LCD_CLEAR); udelay(150); lcd_write_control(info, LCD_RESET); } static const struct fb_fix_screeninfo cobalt_lcdfb_fix = { .id = "cobalt-lcd", .type = FB_TYPE_TEXT, .type_aux = FB_AUX_TEXT_MDA, .visual = FB_VISUAL_MONO01, .line_length = LCD_XRES_MAX, .accel = FB_ACCEL_NONE, }; static ssize_t cobalt_lcdfb_read(struct fb_info *info, char __user *buf, size_t count, loff_t *ppos) { char src[LCD_CHARS_MAX]; unsigned long pos; int len, retval = 0; if (!info->screen_base) return -ENODEV; pos = *ppos; if (pos >= LCD_CHARS_MAX || count == 0) return 0; if (count > LCD_CHARS_MAX) count = LCD_CHARS_MAX; if (pos + count > LCD_CHARS_MAX) count = LCD_CHARS_MAX - pos; for (len = 0; len < count; len++) { retval = lcd_busy_wait(info); if (retval < 0) break; lcd_write_control(info, LCD_TEXT_POS(pos)); retval = lcd_busy_wait(info); if (retval < 0) break; src[len] = lcd_read_data(info); if (pos == 0x0f) pos = 0x40; else pos++; } if (retval < 0 && signal_pending(current)) return -ERESTARTSYS; if (copy_to_user(buf, src, len)) return -EFAULT; *ppos += len; return len; } static ssize_t cobalt_lcdfb_write(struct fb_info *info, const char __user *buf, size_t count, loff_t *ppos) { char dst[LCD_CHARS_MAX]; unsigned long pos; int len, retval = 0; if (!info->screen_base) return -ENODEV; pos = *ppos; if (pos >= LCD_CHARS_MAX || count == 0) return 0; if (count > LCD_CHARS_MAX) count = LCD_CHARS_MAX; if (pos + count > LCD_CHARS_MAX) count = LCD_CHARS_MAX - pos; if (copy_from_user(dst, buf, count)) return -EFAULT; for (len = 0; len < count; len++) { retval = lcd_busy_wait(info); if (retval < 0) break; lcd_write_control(info, LCD_TEXT_POS(pos)); retval = lcd_busy_wait(info); if (retval < 0) break; lcd_write_data(info, dst[len]); if (pos == 0x0f) pos = 0x40; else pos++; } if (retval < 0 && signal_pending(current)) return -ERESTARTSYS; *ppos += len; return len; } static int cobalt_lcdfb_blank(int blank_mode, struct fb_info *info) { int retval; retval = lcd_busy_wait(info); if (retval < 0) return retval; switch (blank_mode) { case FB_BLANK_UNBLANK: lcd_write_control(info, LCD_ON); break; default: lcd_write_control(info, LCD_OFF); break; } return 0; } static int cobalt_lcdfb_cursor(struct fb_info *info, struct fb_cursor *cursor) { u32 x, y; int retval; switch (cursor->set) { case FB_CUR_SETPOS: x = cursor->image.dx; y = cursor->image.dy; if (x >= LCD_XRES_MAX || y >= LCD_YRES_MAX) return -EINVAL; retval = lcd_busy_wait(info); if (retval < 0) return retval; lcd_write_control(info, LCD_TEXT_POS(info->fix.line_length * y + x)); break; default: return -EINVAL; } retval = lcd_busy_wait(info); if (retval < 0) return retval; if (cursor->enable) lcd_write_control(info, LCD_CURSOR_ON); else lcd_write_control(info, LCD_CURSOR_OFF); return 0; } static const struct fb_ops cobalt_lcd_fbops = { .owner = THIS_MODULE, .fb_read = cobalt_lcdfb_read, .fb_write = cobalt_lcdfb_write, .fb_blank = cobalt_lcdfb_blank, .fb_cursor = cobalt_lcdfb_cursor, }; static int cobalt_lcdfb_probe(struct platform_device *dev) { struct fb_info *info; struct resource *res; int retval; info = framebuffer_alloc(0, &dev->dev); if (!info) return -ENOMEM; res = platform_get_resource(dev, IORESOURCE_MEM, 0); if (!res) { framebuffer_release(info); return -EBUSY; } info->screen_size = resource_size(res); info->screen_base = devm_ioremap(&dev->dev, res->start, info->screen_size); if (!info->screen_base) { framebuffer_release(info); return -ENOMEM; } info->fbops = &cobalt_lcd_fbops; info->fix = cobalt_lcdfb_fix; info->fix.smem_start = res->start; info->fix.smem_len = info->screen_size; info->pseudo_palette = NULL; info->par = NULL; info->flags = FBINFO_DEFAULT; retval = register_framebuffer(info); if (retval < 0) { framebuffer_release(info); return retval; } platform_set_drvdata(dev, info); lcd_clear(info); fb_info(info, "Cobalt server LCD frame buffer device\n"); return 0; } static void cobalt_lcdfb_remove(struct platform_device *dev) { struct fb_info *info; info = platform_get_drvdata(dev); if (info) { unregister_framebuffer(info); framebuffer_release(info); } } static struct platform_driver cobalt_lcdfb_driver = { .probe = cobalt_lcdfb_probe, .remove_new = cobalt_lcdfb_remove, .driver = { .name = "cobalt-lcd", }, }; module_platform_driver(cobalt_lcdfb_driver); MODULE_LICENSE("GPL v2"); MODULE_AUTHOR("Yoichi Yuasa"); MODULE_DESCRIPTION("Cobalt server LCD frame buffer driver"); 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